Question: Simplify the following expression: $a = \dfrac{7}{2z + 3} \div \dfrac{2}{7z}$
Explanation: Dividing by an expression is the same as multiplying by its inverse. $a = \dfrac{7}{2z + 3} \times \dfrac{7z}{2}$ When multiplying fractions, we multiply the numerators and the denominators. $a = \dfrac{ 7 \times 7z } { (2z + 3) \times 2}$ $a = \dfrac{49z}{4z + 6}$